The present invention relates to quality of service control in networks, and more specifically, to controlling quality of service for multiple services in a radio network through service group power setting.
Due to the rising popularity of data services such as the Internet, there has been an increased demand for various types of access to these data services. To address this increased demand for access to data services, operators of radio networks have implemented techniques for communication of data through the radio networks. Many portions of the conventional radio networks are reused for these data services. Accordingly, the radio network's air interface resources are shared between the voice and data services. It will be recognized that, depending on the radio access technique, a resource consists of a set of logical or physical channels, (e.g., frequencies for FDMA, timeslots for TDMA, or spreading codes for CDMA), together with a constraint on maximum power or energy for use on these logical or physical channels. When managing the common resource for multiple services in a radio network, bearers of different services having different requirements on channel availability and channel quality, stemming from, e.g., co-channel interference from other cells, should be accounted for.
P. Stuckman et al. “GPRS Radio Network Capacity and Quality of Service Using Fixed and On-Demand Channel Allocation”, in proc IEEE VTC'00 Spring, which is herein expressly incorporated by reference, discloses one conventional method for managing different services in a radio network by dividing the common resource set into smaller isolated parts. Each of these smaller isolated parts are reserved specifically for one service group. Accordingly, channel availability per service group can be controlled through the amount of resources allocated to a particular subset. Channel quality may also be controlled if the resources are arranged such that the same subset allocation is used in all cells in the radio network. Using the same subset allocation in all of the cells in a radio network avoids interference between more aggressive and less aggressive service groups because equally aggressive services will be allocated on the same co-channels in neighboring cells. However, dividing the common resource set into smaller isolated parts results in trunking losses due to the fact that the fewer resources that are pooled together, the less effective each individual resource becomes. Dividing the common resource set requires service mix dependent dimensioning which is difficult to determine prior the division of the common resource set.
One method for managing a common resource for multiple services which avoids the above-identified trunking losses, is to mix services on this same resource. When services are mixed on the same resource, channel availability may be controlled through priority schemes, e.g., assigning blocking sensitive voice services priority over less delay-sensitive data services. For more information on mixing services on the same resource the interested reader should refer to G. Bianchi et al., “Packet Data Services Over GSM Networks With Dynamic Stealing Of Voice Channels”, Proceedings of IEEE GLOBECOM 1995, which is herein expressly incorporated by reference. Because different services typically have different channel quality requirements there are many deficiencies with mixing services on the same resource. For example, when different services are mixed on the same resource the average interference situation on the shared channels is the same regardless of service type. Accordingly, without first accounting for this interference situation, mixing different services on the same resource does not account for the different channel quality requirements of different services.
One method for adjusting the allocation of resources for different quality requirements can be achieved through individual power control. Individual power control is currently used in most direct sequence-CDMA (DS-CDMA) systems, e.g., wide band CDMA (WCDMA), IS-95 or CDMA-2000, as well as TDMA-based systems, e.g., GSM/EDGE systems. In general, individual power control is used to control the power at which individual mobiles or base stations transmit in order to minimize mutual interference between the mobiles or base stations. Since an increase in transmit power for one mobile or base station increases interference to other mobiles or base stations within radio range, this increased transmit power can be considered as increasing the radio resources allocated to the mobile or base station, while the increased interference decreases the radio resources allocated to the other mobiles or base stations. The intent of individual power control is to limit a mobile or base station to transmitting at a minimum power level required to respectively reach a base station or mobile station, with a desired signal strength or quality. For more information on how individual power control can be used as a component to manage multiple services, the interested reader should refer to D. Imbeni et al., “Quality of Service Management for Mixed Service in WCDMA”, in proc IEEE VTC'00 Fall, which is herein expressly incorporated by reference.
One problem with individual power control in GPRS/EGPRS systems is that the amount of individual power control is limited by current standards. Further, in combination with the limited power control provided by the standards, the short duration of data packets for the power control algorithms to converge within renders channel qualities difficult to control through power control. In addition, since these individual power control schemes dynamically regulate power individually for each user to achieve a given link quality target, an increased amount of signaling in the network is required.
Accordingly, it would be desirable to control the quality of service for multiple services that share a common resource without trunking losses and service mix dependent dimensioning. Further, it would be desirable to provide different quality requirements for different services. In addition, it would be desirable to control the interference between service groups to maximize capacity without the increased complexity of individual power control.